code: def test_memory_usage():
      model = (
          preprocessing.StandardScaler()
          | linear_model.LogisticRegression()
      )
  
      # We can't test the exact value because it depends on the platform and the Python version
      # TODO: we could create a table of expected values for each platform and Python version
      assert isinstance(model._memory_usage, str)
  
file_path: river/river/base/test_base.py
imports: from __future__ import annotations
  from river import compose, datasets, linear_model, optim, preprocessing, stats, time_series
label_desc: Use image node_id 5 for calling a global function with example usage: test_memory_usage() without return types